Modern vehicles are often equipped with hardware that facilitates wireless communications between the vehicle and other entities located away from the vehicle. For instance, a vehicle occupant can use a vehicle telematics unit to place a telephone call from the vehicle and carry out conversations over that call. To place such a telephone call, the vehicle occupant can use an interface in the vehicle to dial the telephone number and the vehicle telematics unit will then initiate a cellular call through a wireless carrier system. However, the vehicle occupant may not always know the telephone number of an intended recipient. This can be true when someone knows the vehicle occupants located in nearby vehicles but does not know the telephone numbers associated with those vehicles. Without knowing the telephone number of the vehicle telematics unit, it will not be possible to establish a cellular call with that vehicle. Further, the vehicle occupant may wish to speak with people in multiple vehicles, which would involve knowing the telephone numbers for each vehicle. And even if those telephone numbers where known, it may be difficult for a group of people located in different vehicles to communicate with each other when each vehicle uses a different telephone number. It would be helpful to be able to initiate and establish wireless voice communications between a group of vehicles.